Detonating device



March 1, 1966 E C wH DETONATING DEVICE Filed Sept. 16, 1963 United States Patent O 3,237,560 DETONATING DEVICE Everett C. White, 32E Sicily Drive, Fort Bragg, N.C. Filed Sept. 16, 1963, Ser. No. 309,176 2 Claims. (Cl. 102-29) This invention relates generally to explosive initiators and more particularly to firing devices for detonating explosive charges.

In igniting explosive charges it is necessary to prime at least one of the explosives with an explosion initiator such as a detonator. These detonators usually comprise a small cylindrical container built with an explosive charge and an electrical or time fuse igniting device.

Generally these cylindrical containers are composed of either copper or brass and the explosive charges placed therein are poured, in a heated liquid form, into such container. This is, of course, a very dangerous process as well as an expensive one.

When a metal detonator or cap is used in conjunction with a time fuse igniting device, such igniting device is inserted into an opening in the end of the cylindrical container and a crimping tool is used to form a union between the two. When explosive charges are to be placed under water it is always necessary to waterproof the joint between the detonator and fuse so that such detonator will not become inoperative. This problem of waterproofing rapidly becomes more acute as the depth of water increases. Also the problem increases with the amount of time which the explosive must remain under water prior to detonation.

It has been found that the use of a crimping tool alone will not waterproof a detonator. In actual use, most metal detonators are first crimped, then wound very tightly with a rubberized .or plastic tape and then covered with a type of glue to further insure complete water proofing. This isa long involved process and is far from fool-proof even at best.

Another problem which has arisen in the use of detonators is the necessity for having two different types of blasting cans, one for time fuses and another for electric igniters. In other words, storage must be provided for two different types of blasting caps depending on the type of fuse used. This is most inconvenient and even dangerous in that there is always the danger of accidental ignition of the caps and by having to have two separate types in storage the danger is multiplied.

It is therefore an object of the present invention to provide an explosive detonator capable of being used in conjunction with both time fuses and electric igniters.

Another object of the present invention is to provide a waterproof blasting cap which may be fired by the use of either a time fuse or an electric igniter.

A further object of the present invention is to provide a blasting cap manufactured in two separate parts of a fusible plastic material so that each part or portion of such cap may be separately loaded with explosive materials either in solid or cold form and then each section may be united with a glue or solvent material to form a unitary structure without the use of heat sealing or other explosively dangerous processes.

Another object of the present invention is to provide a combination blasting cap composed of a cylindrical housing of a fairly rugged material having a flexible pliable sleeve connected at one end thereof in such a manner as to provide a water tight joint between such cap and a time fuse by use of a clamp, string, wire or other securing means.

Other objects and advantages of the present invention will become apparent and obvious from a study of the Patented Mar. 1, 1966 ice following description and the accompanying drawings which are merely illustrative of the present invention.

In the drawings:

FIG. 1 is a sectional view taken from lines 1-1 of FIG. 2 disclosing a preferred embodiment of the present invention;

FIG. 2 is a sectional view taken from lines 22 of FIG. 1 showing the electric igniter;

FIG. 3 is a perspective of the present invention disclosing the blasting cap of the present invention in operative relation with both an electric igniter and a time fuse.

With further reference to the drawings, FIG. 1 discloses a blasting cap 10 having generally cylindrical upper and lower wall portions 11 and 12 respectively. One end of the lower wall portion 12 has a concave, generally conical, end portion 13. On the open end of the lower wall portion 12 is provided a longitudinally disposed flange 15 with an internal shoulder 14.

One end of the upper wall portion 11 is provided with a longitudinally disposed flange 16 and an external shoulder 17 for co-operatively engaging, in overlapping relation, the flange and shoulder of the lower portion 12 to provide, when proper sealent is used, a strong, water impregnable, airtight union between such wall portions.

An outwardly projecting flange 18 is provided about the upper wall portion 11 at the end opposite the shoulder 17 and flange 16. Flange 18 adapts the explosive primer to be inserted into and rigidly reside in a primer cavity in the explosive charge.

A sleeve portion 19 composed of a flexible, pliable material is fused or otherwise secured to the upper wall portion 11 in such a manner that a water tight union be tween such sleeve and wall is provided.

Imbedded within the wall portion 11 of the blasting cap 10 and extending from just above the retainer ring or flange 18 to a point longitudinally below said flange are electrical conduits 20. The lower ends of these conduits terminate in inwardly projecting prongs 21. Connected between such prongs 21 is an incandescent material 22 for igniting the explosive material within the blasting cap 10.

In the manufacture of blasting caps of the present invention it is contemplated that a base charge 23 of explosive material in the form of either a dry powder, a cold paste or a dry slug may be placed in the lower portion of the blasting cap thereby eliminating the very dangerous operation of loading such explosive materials into the cap in a heated liquid form.

A waterproof, thin plastic film 24 is provided within the upper wall portion 11 to protect the explosives within the cap from weather and dampness while such caps are in storage. This film or seal is constructed in such a way that the flash from a time fuse will readily burn through it. Just below the seal 24 is provided a flash charge 25 which is ignited by the flame produced by the time fuse. This charge 25 may be placed in the cap in a similar physical condition as the base charge 23 and in such a manner that it passes around and has imbedded therein the inwardly projecting prongs 21 and incandescent material 22. After the flash charge 25 has been loaded, a priming charge 26 is packed thereon and extends to the lower portion of upper wall portion 11 so that when lower wall portion 12 and upper wall portion lever 11 are cooperatively engaged, priming charge 26 will be in contact with base charge 23.

Once the upper and lower ortions have been properly loaded with their respective explosive charges, the two portions may be united by placing glue, solvent material or other suitable sealing media on the contactive surfaces offlanges 15 and 18 and shoulders 14 and 17 and placing such flanges and shoulders in fitted, co-operative relationship. Thus by uniting the upper and lower portions of the blasting cap in a waterproof manner without the use of heat or highly dangerous uniting methods a safer and better blasting cap is formed.

It will, of course, be appreciated that due to the concave, generally conical end portion 13, the blast from the cap will be more concentrated in one direction due to the application of the principles commonly known as the shaped charge or Monroe Effect. In other words, the concave end portion directs the blast of the cap in a line parallel to the longitudinal axis of the detonator thereby more quickly and more completely igniting the main explosive charge.

In actual use of the detonator or blasting cap of the present invention the person in charge of the blasting operation removes from storage the number of caps necessary for detonating the explosive charges. By using the detonator of the present invention it is not necessary, prior to the actual arming of the explosive, to determine whether a time fuse or an electric ignition system would best serve the purpose.

If a time fuse is desired to ignite the detonator, such time fuse may be inserted into the hollow portion 27 of the blasting cap 10. Then a string, wire, clamp, or other securing means 28 may be drawn securely about the flexible sleeve 19 thereby insuring a completely water tight joint between the time fuse 29 and the blasting cap 10.

If an electric ignitor is desired, by using the same universal blasting cap, a securing means 28 may be used to tie off the resilient sleeve 19 so that no moisture will be allowed to enter the hollow portion 27. Then the electrical conduits 20 are attached to a source of electrical potential 30 so that as current passes through such conduits the incandescent material will ignite the priming charge thereby firing the detonator.

It is obvious that the present invention has the advantages of being cheap to manufacture, safe to transport and store, solves the problem of having two separate kinds of blasting caps for different types of igniting devices and allows a completely waterproof joint to be made between the fuse and the detonator which has hereinbefore been difiicult if not impossible.

The terms upper, lower, and so forth, have been used herein merely for convenience in the foregoing specifications and in the appended claims to describe the detonating device and its parts as oriented in the drawings. It is to be understood, however, that these terms are in no way limiting to the invention since the detonator may obviously be disposed in many different positions when it is used.

The present invention may be carried out in other specific ways than those herein set forth without departing from the spirit and essential characteristics of the invention. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive, and all changes coming within the meaning and equivalency range of the appended claims are intended to be embraced therein.

What is claimed is:

1. An explosive primer adapted to at least partially reside in an explosive charge for detonating the same comprising a generally cylindrical housing which includes a first and second tubular section, said first tubular section being enclosed at one end for receiving a base charge and being connected to one end of said second tubular section at the other end, said second tubular section having a waterproof heat fracturable seal selectively located along the inner portion for dividing said second tubular section into a first and second chamber, said first chamber receiving a flash charge adjacent said waterproof seal and a priming charge adjacent said flash charge, said priming charge also being in contact with said base charge when said ends of said tubular sections are connected, said second chamber of said second tubular section having an open end for receiving a length of a time fuse; a resilient sleeve secured to said open end of said second chamber for tightly encompassing a section of said time fuse; and electricalconduits imbedded in the wall of said second tubular portion with one set of ends extending exteriorly therefrom and the other ends projecting inwardly into said housing and being imbedded in said flash charge, said projecting ends being connected by an incandescent material whereby said explosive primer may be ignited electrically or by said time fuse.

2. The explosive primer of claim 1 wherein said second tubular section is provided with an outwardly projecting flange for adapting said explosive primer to be securely positioned in said explosive charge.

References Cited by the Examiner UNITED STATES PATENTS 2,178,723 11/1939 Forsyth 102-29 2,388,310 11/1945 Curtiss 102-29 2,617,326 11/1952 Morris '86-1 2,796,834 6/1957 McCaflrey et al. 102-27 2,942,513 6/1960 Seavey et al. '861 2,996,987 8/1961 Paul 10228 3,021,786 2/1962 Miller et al 102-27 3,037,452 6/1962 Cook et al 10224 3,064,573 11/1962 Blair et a1 102 24 BENJAMIN A. BORCHELT, Primary Examine).

SAMUEL 'FEINBERG, Examiner.

G. I. PETERSON, G. H. GLANZMA-N,

Assistant Examiners. 

1. AN EXPLOSIVE PRIMER ADAPTED TO A LEAST PARTIALLY RESIDE IN AN EXPLOSIVE CHARGE FOR DETONATING THE SAME COMPRISING A GENERALLY CYLINDRICAL HOUSING WHICH INCLUDES A FIRST AND SECOND TUBULAR SECTION, SAID FIRST TUBULAR SECTION BEING ENCLOSED AT ONE END FOR RECEIVING A BASE CHARGE AND BEING CONNECTED TO ONE END OF SAID SECOND TUBULAR SECTION AT THE OTHER END, SAID SECOND TUBULAR SECTION HAVING A WATERPROOF HEAT FRACTURABLE SEAL SELECTIVELY LOCATED ALONG THE INNER PORTION FOR DIVIDING SAID SECOND TUBULAR SECTION INTO A FIRST AND SECOND CHAMBER, SAID FIRST CHAMBER RECEIVING A FLASH CHARGE ADJACENT SAID WATERPROOF SEAL AND A PRIMING CHARGE ADJACENT SAID FLASH CHARGE, SAID PRIMING CHARGE ALSO BEING IN CONTACT WITH SAID BASE CHARGE WHEN SAID ENDS OF SAID TUBULAR SECTIONS ARE CONNECTED, SAID SECOND CHAMBER OF SAID SECOND TUBULAR SECTION HAVING AN OPEN END FOR RECEIVING A LENGTH OF A TIME FUSE; A RESILIENT SLEEVE SECURED TO SAID OPEN END OF SAID SECOND CHAMBER FOR TIGHTLY ENCOMPASSING A SECTION OF SAID TIME FUSE; AND ELECTRICAL CONDUITS IMBEDDED IN THE WALL OF SAID CONTROL TUBULAR PORTION WITH ONE SET OF ENDS EXTENDING EXTERIORLY 